Three small multi-band planar inverted-F antennas (PIFAs) are presented. They have been developed to be used in future small multi-standard handsets. Mobile communication (GSM1800, UMTS), wireless local area network (WLAN) (IEEE 802.11b, HiperLAN2) and wireless personal area network (WPAN) (Bluetooth) standards have been envisaged. Prototypes have been designed, fabricated and tested. Good agreement has been obtained between numerical simulations and experimental results

A small multi-band microstrip Planar Inverted-F Antenna (PIFA) is presented. It is intended to be used in small handsets for mobile communication systems, Wireless Local Area Networks (WLAN) and Wireless Personal Area Networks (WPAN) applications. The research effort as been focused in miniaturisation and adequate multi-band behaviour at the GSM1800, UMTS and IEEE 802.11b/Bluetooth frequency bands. A prototype has been designed, fabricated and tested. Good agreement has been obtained between numerical simulations and experimental results. Introduction. The need for triple-band antennas has been created mainly by the nowadays overwhelming importance of the mobile communications market and the recent explosion of WLAN services. The terminals for 3G mobile communication systems must be 2G compatible. In Europe that means support of both GSM and UMTS. Furthermore the growing importance of WLANs and WPANs is already demanding specific attention. Therefore operation with other standard, for instance IEEE 802.11b and Bluetooth, have to be supported. In this paper a small triple-band PIFA element is described. It is intended to be used in small multi-standard handsets of future mobile communication systems integrating both cellular and WLAN/WPAN services. Several dual-band and triple-band antenna configurations have been proposed recently by Wong (1), Song et al. (2), Manteuffel et al. (3), and Brissos et al. (4, 5), on this same topic. Antenna Configuration. The geometry of the triple-band PIFA element is shown in figure 1 (dimensions in mm). The width of the L-shaped slot is 1.5 mm and it has a short side with 9.6 mm and a long side with 21.1 mm. The antenna element is placed 4 mm from the substrate borders. The horizontal and vertical distances of the coaxial feed probe from the patch borders are 13 mm and 4 mm, respectively. A 1.575 mm thick Rogers Duroid 5880TM substrate with εr=2.20 and tan δ=0.001 (@ 10 GHz) is used on top of a 13 mm hair gap. Antenna Specifications. The antenna element has been designed using ENSEMBLE® software tool (6). The external dimensions of the patch and the feed point location have been optimised to provide the GSM1800 (f1 = 1795 MHz) and UMTS (f2 = 2035 MHz) resonances. The L-shaped slot is intended to introduce the IEEE 802.11b/Bluetooth resonance (f3 = 2441.75 MHz).